Answer by Kellycheeseburger10. Confidence votes 86. When a light is shined into an eye the pupil contracts gets smaller because the eye doesn't need all the light being presented to it. If the light is taken away the pupil dilates. PS like the eye gets bigger in the dark.
The ancient Egyptians did not know the hard setting lime plaster invented by the Greeks, but used instead a mixture of gypsum and quartz with small amounts of lime [5] when working with stone.This was not as disastrous in the dry climate of Egypt as it would have been under wetter conditions.ost of the ancient Egyptian buildings have disappeared leaving no trace. Built of sun baked bricks made of Nile mud and straw, houses, palaces and city walls crumbled when they stopped being looked after.
Gypsum has been used in construction since the days of ancient Egypt, where it was used in building the Pyramids. Some of this construction is still visible over 5,000 years later, a tribute to gypsumâs durability as a building material. Alabaster is a form of gypsum used both in building and as a decorative material. In the 18th century, the French chemist Lavoisier began modern research on gypsum by studying its chemical properties. Large deposits of gypsum were discovered near Paris, and âPlaster of Parisâ became a popular building material. Plaster of Paris is raw gypsum that is chemically altered by heat to remove much of the water naturally occurring in gypsum. French farmers also used natural gypsum as a soil additive to improve crop yields. Benjamin Franklin brought this idea to America, and the use of gypsum in agriculture expanded dramatically when gypsum beds were discovered in New York State. Later deposits were found across the country, notably near Ft. Dodge, Iowa.